US Patent Publication 2002-0102059 A1 discloses a prior art actuator system fabricated on a silicon substrate as the micro-electro-mechanical system for switching an optical path. The system includes an actuator carrying a shutter which selectively interrupts an optical path. The actuator is movably supported to the substrate and is formed with an electrode which is cooperative with a driving electrode fixed on the substrate to develop an electrostatically attracting force therebetween for shifting the actuator between two operative positions, one is an ON-position of receding the shutter from the optical path and the other is an OFF-position of projecting the shutter into the optical path. A mechanical latch is provided in the system to latch the actuator in the OFF-position. For this purpose, the actuator is formed at its one end with a catch which comes into latching engagement with dents when the actuator moves into the OFF-position. The dents are formed respectively at the ends of latching electrodes which are additionally incorporated on the substrate. Further, In order to unlatch the actuator, the system requires additional driving electrodes for driving the latching electrodes to move it electrostatically for disengaging the detents from the catch of the actuator. Thus, unlatching of the actuator is accomplished in the prior art system by introducing an additional set of electrodes other than those designed to drive the actuator itself. The inclusion of the additional electrodes largely detracts from the concept of the MEMS of giving a micro-structure, and would be more critical when the actuator is required to be latched not only in the OFF-position but also in the ON-position since it requires a further set of electrodes for latching the actuator in the ON-position.